Low-Volume High-Intensity Race-Pace Training in Finswimmers

This prospective single-group case series will describe individual responses to a 9-week low-volume, high-intensity race-pace training block in approximately seven finswimmers from the Antioquia Underwater Activities League (LASA), Colombia. The intervention will be oriented towards race-specific swimming paces and will include repeated swimming efforts prescribed according to each athlete's main competitive event. External training load, heart rate, rating of perceived exertion, pace stability, and sport performance will be monitored throughout the block. The primary outcome will be the change in performance time in each athlete's main competitive event from baseline to post-intervention. The study will use an intra-individual descriptive approach and will not include randomisation, a control group, or causal inference.

Inclusion Criteria: * Finswimmers affiliated with the Antioquia Underwater Activities League (LASA). * Regular participation in finswimming training. * A defined main competitive event. * Availability to complete the 9-week follow-up period. * Ability to complete high-intensity swimming training according to the regular sport programme. * Written informed consent from adult participants. * For participants under 18 years of age, written informed consent from a parent or legal guardian and written assent from the participant. Exclusion Criteria: * Active musculoskeletal injury. * Relevant pain or acute illness at baseline. * Medical restriction for high-intensity swimming exercise. * Inability to complete the planned follow-up. * Withdrawal of consent or assent. * Insufficient attendance or incomplete records for the main study variables. * Any condition judged by the research team or coaching staff to compromise participant safety during high-intensity swimming.